manley stainless..

Did that motor have zero gap rings?

WOW there stuff is pretty good did you spin big rpm?

I did.

"The low lift profiles were designed for street and marine use. The low lift adds dependability and reliability for extend-
ed use applications. The high lift versions of the hydraulic rollers are designed for all out applications where high lift
is desired because of cylinder head or engine modifications. They function well for street and strip. These lobes run
well in big cubic inch marine engines."

Crane also has a 680 lift 244 grind they say is ok for a marine application.

Anyone running 680, 700 lift hyd cams going 300 hours on their valvetrains? I know its done everyday with .360 lobes. Anyone doing it with .400+ lobes ?

theres a reason a stock GM roller big block with a whopping .483 lift, can go 1500 hours, and a .612-.630 merc only goes 300 hours or so? Safe to assume increasing lift adds power, while reducing valvetrain life generally?

How much power is gained even with 335 afrs, by going from a .370 lobe to a .400 lobe? How much of a reduction in valvetrain life ? How much faster will the boat go?

no, file fit, I can't remember specs, been a while those were my 460's with merlin heads.. years ago

5000 max

What kind of power?

MT - I think what may be happening here is your assumption that everyone uses the same/ nearly the same shape lobes other than what would change from adding more max lift.

I'm sure you know you can add a lot more detail in a painting with a 1" brush vs a 4" brush, just like you can grinding cams with a 10" grinding wheel vs a 18" wheel, or even better , say a 6" wheel vs an 18" wheel. Say like, slower opening and closing ramps, but a faster higher rest of lobe, or changing things anywhere you want.

Larger wheels cut cams faster. Faster is needed when you make more cams.

There is a lot of things that go on with cams....a lot that none of us talk about and most of us won't comprehend on the level that we like too.

If I need another 30hp I`ll skip the whole more aggressive, custom $500 cam and just turn up the boost.


http://cimg4.ibsrv.net/gimg/www.club...83307ccc4b.jpg

Yes, the story about the lobe can be told as well by having measurements at various locations. Some cam grinders/spec'ers will provide you with those measurements, and some dont.

While yes, alot can be done when the cam is being ground, and yet, there are still certain limitations that simply cannot be changed.

With that being said, we are talking about things, that should be discussed with a person who grinds and designs lobes for a living day in and day out.

Have you ran any bbc shorter duration cams with larger than typical lobes in some offshore stuff for any amount of longevity ? If so, what was the setup?